This is how I ask my contacts on WhatsApp to move to Signal.

Each message to be sent on WhatsApp/Signal is separated by a horizontal line. Separating them makes WhatsApp/Signal render link previews nicely - wait for the preview to appear before sending each message. After copy-pasting from Lemmy to WhatsApp/Signal, you may have to correct the formatting by adding [Shift+Enter] where a line feed has disappeared, or to re-bold subheadings by selecting text and clicking the [B]-button.

It is not safe for Europeans to use WhatsApp.

WhatsApp is owned by the US company Meta, whose largest shareholder and decision-maker is Mark Zuckerberg, a billionaire Trump supporter. Meta’s business model has always been based on the use and resale of data extracted from and spied on users of its free services for all manner of purposes. The $16 billion acquisition of WhatsApp was not an act of charity, but an investment designed to get users’ conversations onto their servers.

WhatsApp’s source code is secret, so no impartial party can verify whether the app’s owner is able to read all message histories or not. Even if this were not currently possible, new updates are released constantly, and a backdoor could be added at any time – for example, if Trump ordered it – and under US law, a company operating there is obliged to comply with government orders.

https://en.wikipedia.org/wiki/WhatsApp#Switzerland
"
In December 2021, the Swiss army banned the use of WhatsApp and several other non-Swiss encrypted messaging services by army personnel. The ban was prompted by concerns of US authorities potentially accessing user data for such apps because of the CLOUD Act.
"

https://en.wikipedia.org/wiki/Lawsuits_involving_Meta_Platforms
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... collecting biometric data of their Facebook and Instagram users without their consent and then sharing it with third parties and not deleting it in time, despite Meta announcing that it would delete all data it had collected ...
"

https://en.wikipedia.org/wiki/Mark_Zuckerberg#Politics
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Zuckerberg was one of a handful of technology leaders positioned prominently at Trump's inauguration. ... In January 2025, he said: "We now have a U.S. administration that is proud of our leading companies, prioritizes American technology winning and that will defend our values and interests abroad."
...
Zuckerberg has expressed opposition to EU regulations of his company saying "we're going to work with President Trump to push back on governments around the world that're going after American companies."
"

The leakage of detailed information to foreign powers is dangerous for Europe, particularly now that artificial intelligence can sift through mountains of data and identify ways in which Europe could be most effectively undermined by manipulating individual citizens.

Europeans mostly use US software and online services, and the data collected from these enables highly accurate micro-targeted advertising.

It is suspected that Brexit and Trump were brought about through the use of personalised propaganda.

https://www.theguardian.com/technology/2017/may/07/the-great-british-brexit-robbery-hijacked-democracy

https://en.wikipedia.org/wiki/Surveillance_capitalism

I recommend replacing WhatsApp with a similar app called ‘Signal’, which is open-source and developed by a foundation.

Messages don't move between Signal and WhatsApp, but they can be ‘shared’ one by one from one app to the other.

https://en.wikipedia.org/wiki/Signal_(software)

On Signal, finding contacts by phone number has sometimes been a bit hit-and-miss, but searching by username has always worked. You can choose your username in Signal’s settings. When you share your username, your phone number is not revealed to the other party in the conversation unless you specifically provide it, just as with email. Setting up Signal without a phone number is a paid feature.

When the person has moved from WhatsApp to Signal, I send them the following messages.

Signal can save your message history to its own cloud, but this does not happen automatically; the setting can be found under Settings/Backups. With the free cloud package, storage space for media files is limited.

If you do not use Signal’s paid cloud service, you can keep your entire message history (including images and videos) safe from device damage or loss using one of the following methods:

• Install Signal on another device that you are unlikely to lose at the same time as your other device, for example in a fire or burglary. Your chat history will synchronise via an internet connection whilst the devices are switched on.
• Download a backup file from Signal regularly and store it somewhere else. A file left on your phone will likely end up in your phone’s operating system’s backup cloud, provided this feature is switched on and covers the folder where you saved the file.

If an old, decommissioned device contains an old message history that you wish to transfer to new devices, simply update Signal to a sufficiently recent version that is capable of synchronising histories between devices. Check whether media files older than the free cloud's time limit were transferred or if you need to pass a backup file.

You can improve the quality of the photos and videos you send by going to Settings/Data usage/Media quality: High. There is no ‘Original quality’ option.

You can bypass compression and resizing, which reduce quality, by hiding media files inside a zip file (or equivalent), which Signal will send as is. This is useful for maximising the quality of an image sent for printing, or if the image contains text that is so small it cannot be read unless it is in its original quality.

If the person is interested in privacy and information security, I send them these:

Try going somewhere without being spotted by a surveillance car made in the US or China. A European in Europe cannot escape an agent of a foreign power.

- Oblivious human drone swarm attack -
Pre-emptive manipulation of society by nudge swarms around vigilant targets, as orchestrated by surveillance capitalist companies

Surveillance capitalist companies study people to better manipulate their behaviour by advertisements. That skill can be used to attack a vigilant target using oblivious mediators as a drone swarm delivering a payload.

https://lemmy.world/post/52470551 (needs JavaScript)

Another way to the same post:
https://piefed.social/c/aboringdystopia@lemmy.world/p/2429126/pre-emptive-manipulation-of-society-by-nudge-swarms-around-vigilant-targets-as-orchestr

Another way to the same post:
https://scribe.disroot.org/post/11576201

For your computer and tablet running Microsoft Windows or Google Chrome operating systems, Fedora Linux is a good option (there are many others). Linux can also be installed to Apple devices. If you prefer Apple style or must use a touchscreen, choose the default version of Fedora (or Debian) with Gnome desktop environment, but if you prefer Windows style, choose the one with KDE Plasma. Linux Mint also resembles Windows, and is slightly easier to set up because you can get proprietary codecs for playing media files by checking a box, while in Fedora you have to do it on the terminal.

For your Android phone or tablet, several alternative operating systems are available. The AOSP-based ones are almost entirely Android-compatible, best of which is GrapheneOS. The Linux-based ones (Jolla phone, Nura, Ubuntu Touch) can also run Android apps, but I haven't tried them.

GrapheneOS - maximum security and privacy for phones and tablets

• More Android apps than on other deGoogled OSs
• Very secure (hack-resistant) if correctly set up and used
• Easy to install to the few phones it accepts (some Google, some Motorola 2027)
• Beginner-hostile, complicated manual setup
• Good website and active forum
• NextCloud works - prefer GrapheneOS sponsors, consider Murena to support /e/OS (another deGoogled Android-compatible OS, beginner-friendly, technically inferior, installable to more devices)

I use /e/OS on a Sony phone:
https://www.quora.com/How-does-Murenas-custom-e-OS-compare-to-Googles-Android/answer/Harri-K-Hiltunen

The battery last a week in sparse use without Android's constant surveillance wasting energy.